本論文將呈現一可解析的方法(analytical method)，設計一可重組式微波共振器(reconfigurable microwave resonators)結構，此解析的方法著重於，如何找到共振器上可重組的極點與零點(reconfigurable poles and zeros)，使得在應用可變電容二極體(varactor diode)製作的可重組式共振器，能有一個準確且有效率的設計指南。再來，利用此可重組式共振器將可實現一具有頻寬可重組效果(bandwidth reconfigurability)的微波帶通濾波器(bandpass filter，BPF)。 根據本論文提出的方法設計的可重組式濾波器，在調整頻寬的範圍內，可得到低通帶介入損耗(in-band insertion loss)的結果，再來，當頻寬變化時，濾波器的選擇度(selectivity)幾乎維持不變。最後再實現電路時，使用共平面波導(coplanar-waveguide)結構，完成本次論文的實驗，並且得到通帶內的介入損耗恆小於1.8dB，折返損耗(return loss)恆大於10dB。更重要的是，比例頻寬(fractional bandwidth，FBW)可由54.1%(中心頻率3.03GHz)變化到90.1%(中心頻率2.64GHz)。 An analytical design method for reconfigurable microwave resonant structures is presented. The method aims for how to position the reconfigurable poles and zeros of the resonators. The proposed analytical method is essentially poised for an efficient and accurate design of the reconfigurable microwave resonators loaded with varactors. Furthermore, a design approach for microwave bandpass filter (BPF) with bandwidth reconfigurability is also presented. Compared to the reported design methodology, the presented approach aims for the design of the reconfigurable BPF with relatively wide bandwidth tuning range, as well as low in-band insertion loss. Furthermore, the filter selectivity remains almost unchanged while the fractional bandwidth varies. The proposed design approach is experimentally verified through the demonstration of a coplanar-waveguide BPF design. As a result, passband insertion loss is less than 1.8dB, and the return loss is greater than 10dB. Most importantly, the FBW has a relatively high reconfigurability ranging from 54.1% (at 3.03 GHz) to 90.9% (at 2.64 GHz).
